util/caps.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 local base64 = require "util.encodings".base64.encode;
  10 local sha1 = require "util.hashes".sha1;
  11
  12 local t_insert, t_sort, t_concat = table.insert, table.sort, table.concat;
  13 local ipairs = ipairs;
  14
  15 local _ENV = nil;
  16 -- luacheck: std none
  17
  18 local function calculate_hash(disco_info)
  19         local identities, features, extensions = {}, {}, {};
  20         for _, tag in ipairs(disco_info) do
  21                 if tag.name == "identity" then
  22                         t_insert(identities, (tag.attr.category or "").."\0"..(tag.attr.type or "").."\0"..(tag.attr["xml:lang"] or "").."\0"..(tag.attr.name or ""));
  23                 elseif tag.name == "feature" then
  24                         t_insert(features, tag.attr.var or "");
  25                 elseif tag.name == "x" and tag.attr.xmlns == "jabber:x:data" then
  26                         local form = {};
  27                         local FORM_TYPE;
  28                         for _, field in ipairs(tag.tags) do
  29                                 if field.name == "field" and field.attr.var then
  30                                         local values = {};
  31                                         for _, val in ipairs(field.tags) do
  32                                                 val = #val.tags == 0 and val:get_text();
  33                                                 if val then t_insert(values, val); end
  34                                         end
  35                                         t_sort(values);
  36                                         if field.attr.var == "FORM_TYPE" then
  37                                                 FORM_TYPE = values[1];
  38                                         elseif #values > 0 then
  39                                                 t_insert(form, field.attr.var.."\0"..t_concat(values, "<"));
  40                                         else
  41                                                 t_insert(form, field.attr.var);
  42                                         end
  43                                 end
  44                         end
  45                         t_sort(form);
  46                         form = t_concat(form, "<");
  47                         if FORM_TYPE then form = FORM_TYPE.."\0"..form; end
  48                         t_insert(extensions, form);
  49                 end
  50         end
  51         t_sort(identities);
  52         t_sort(features);
  53         t_sort(extensions);
  54         if #identities > 0 then identities = t_concat(identities, "<"):gsub("%z", "/").."<"; else identities = ""; end
  55         if #features > 0 then features = t_concat(features, "<").."<"; else features = ""; end
  56         if #extensions > 0 then extensions = t_concat(extensions, "<"):gsub("%z", "<").."<"; else extensions = ""; end
  57         local S = identities..features..extensions;
  58         local ver = base64(sha1(S));
  59         return ver, S;
  60 end
  61
  62 return {
  63         calculate_hash = calculate_hash;
  64 };